The '236 patent discloses the use of an interlock mechanism for preventing actuation of the bale pusher until such time as the bale has been dumped from the chamber onto the ground. Thus, unless the bale has left the chamber, the sensor of the interlock mechanism does not allow the pusher to be operated, even though the tailgate has been fully raised. This prevents the pusher from accidentally being operated before the bale comes out, which could otherwise enable the bale to leave the chamber after the pusher was fully extended and to become trapped between the extended pusher and the frame of the baler. Although the interlock mechanism normally performs quite well, in certain crop conditions the bale may emerge from the bale chamber so slowly that, even though the sensor of the interlock may have been tripped, the bale does not reach the ground before the pusher actuates.